Question

Which methods will help you properly identify pH with indicator paper? Check all that apply.

Set a piece of pH paper in front of each solution before testing to keep organized.

Dip the pH paper into each test tube and lay it on the table to let it change color.

Use a transfer pipet to remove a few drops from the solution to drop onto the paper.

Wait a minute or so before reading color.

Use the same piece of indicator paper for each solution to conserve paper.

Answer 1

Correct choices:
- Set a piece of pH paper in front of each solution before testing to keep organized.
- Use a transfer pipet to remove a few drops from the solution to drop onto the paper.
- Wait a minute or so before reading color.

Why:
- Placing a labeled strip by each tube helps keep results matched to the correct sample.
- Using a pipet to put drops on fresh paper avoids contaminating the bulk solution and gives a small, well-defined test spot.
- Allowing a short time for the indicator to develop ensures you read the true color (follow the paper’s specific timing recommendation).

Do not:
- Lay a dipped strip on the bench (it can pick up contaminants or spread liquid).
- Reuse the same strip for multiple solutions (this cross-contaminates and ruins the readings).